Validation of LAI and assessment of winter wheat status using spectral data and vegetation indices from SPOT VEGETATION and simulated PROBA-V images

Due to the information gap between the VEGETATION sensors and Sentinel-3 mission, the Belgian state decided to build a small satellite, Project for Onboard Autonomy-Vegetation (PROBA-V), to ensure the continuity of the data record for vegetation studies. In this study, simulated PROBA-V data generated by the Landsat Thematic Mapper (TM) were used to evaluate the potential of this mission to assess winter wheat status. The root mean square error (RMSE) of PROBA-V's leaf area index (LAI), which was generated using the exponential method and the interpolation method, is 0.33 and 0.96 for March 2011 and 1.40 and 3.33 for May 2011, respectively. Système Pour l'Observation de la Terre (SPOT) VEGETATION's LAI does not show a significant relationship with the reference LAI values except for the LAI values during the stem elongation 100% phenological stage generated using the exponential method (correlation coefficient, r = 0.91; p = 0.01). For the tillering and stem elongation 100% phenological stages, linear regression models for the fraction of absorbed photosynthetically active radiation (FAPAR) with PROBA-V's normalized difference vegetation index (NDVI) were developed (coefficient of determination, R ², of 0.94 and 0.88). Exponential models for LAI (R ² of 0.91 and 0.93) and fresh weight of above-ground biomass (AGBf) (R ² of 0.90 and 0.93) with PROBA-V's near-infrared (NIR) and visible and near-infrared bands (VNIR B2) were developed accordingly. The assessment of winter wheat status showed that the highest and the lowest values of PROBA-V's simulated data (SD), i.e. NDVI, normalized difference water index (NDWI), and LAI of Field 2 and Field 4, correspond to the ground-measured biometric parameters.     

Synthesis and characterization of {Fe2CuO} clusters as precursors for nanosized catalytic system for Biginelli reaction

The novel μ₃-oxo-bridged heterotrinuclear iron(III)-copper(II) trichloroacetates of the composition [Fe₂CuO(CCl₃COO)₆(THF)₃] (1a) and [Fe₂CuO(CCl₃COO)₆(4-DMAP)₃] (1b) have been synthesized and characterized by X-ray crystallography, IR and Mossbauer spectroscopy. These clusters were used as precursors for the synthesis of the nanosized catalytic system (～5–6 nm of γ-Fe₂O₃/CuO), which works as an efficient organic phase catalyst (～0.02 mol%) in a one-pot three component Biginelli synthesis.     

Daily doses of light in relation to the growth of Scenedesmus obliquus in diluted three‐phase olive mill wastewater

BACKGROUND: The use of olive‐oil mill wastewater (OMW) from a three‐phase centrifugation process used in the olive‐oil industry, has been studied in relation to the production of the microalga Scenedesmus obliquus CCAP 276/3A. The chemical characteristics of OMW indicated nitrogen deficiency. RESULTS: S. obliquus is able to assimilate nutrients present in a culture medium (water‐OMW 5%) and grow at its maximum specific growth rate of 0.026 h^?1, both under mixotrophic as well as heterotrophic conditions. The different daily doses of light (DDL) used, in the range 0–36 E m^?2 d^?1, determined light‐limited and light‐inhibited cultures. The light‐inhibited mixotrophic cultures bore characteristics similar to those of the heterotrophic cultures, and became more so when the dose of light received was higher. The low protein yield (258 mg g^?1) and high percentage of carbohydrates of the biomass (65.8%) confirmed a nutritional‐stress situation associated with nitrogen limitation. CONCLUSION: The similarity between the fatty‐acid composition of the heterotrophic and mixotrophic cultures strongly inhibited by light appeared to indicate the cancelling of the photosynthetic behaviour of the cells at high DDL values. The biomass generated can be used for biofuels. The maximum elimination of biological oxygen demand (BOD₅) per unit of biomass was achieved in the heterotrophic cultures. Copyright © 2009 Society of Chemical Industry     

Effect of α and γ polymorphs of alumina on the preparation of MgAl2O4-spinel-containing refractory cements

The use of aluminous refractory materials containing MgAl₂O₄-spinel has led to a major breakthrough in the service life of refractory coatings applied in the industries and in the quality of the products.Many researches have been conducted to improve the synthetic procedures in order to reduce the production cost of these materials. In this way, refractory cements involving in situ generated spinel phase have been obtained from mixtures of active alumina and dolomites. Other investigations have demonstrated that γ alumina is advantageous in comparison with the α polymorph in the synthesis and sintering properties of pure MgAl₂O₄-spinel.In this article, the performance of both polymorphs of alumina, used as raw materials in the preparation of the refractory cements, along with dolomite proceeding from Olavarría, in the centre of Buenos Aires Province (Argentine), is compared.The thermal and structural changes which take place during the firing of the batches up to 1450 °C were studied by the combination of diffractometric and infrared spectroscopy data, at the most remarkable reaction steps.According to these results, the study of phase changes within the investigated thermal range allowed to establish the main differences in the composition of both mixtures in each firing step. Independently of the type of alumina used, a mixed phase product consisting of spinel, as a major phase, accompanied by CaAl₂O₄ (CA) and CaAl₄O₇ (CA₂), as secondary phases, was obtained. In addition, it was found that the formation of these phases at lower temperature is favoured by γ-Al₂O₃.     

Traceability as a means to investigate supply chain sustainability: the real case of a leather shoe supply chain

In recent years, the growing attention to environmental challenges has shown that these issues are becoming of more and more interest to both research and industry. Companies are expected to ensure their products are fully traceable and more sustainable, which requires the involvement of all of the actors in the production network. According to this aim, this study proposes a structured approach that uses the traditional traceability concept as a means to identify the main information needed to assess environmental impacts along the whole supply chain (SC). The proposed approach is composed of four main steps: (i) SC modelling to identify all stakeholders and their inter-relations, (ii) data sharing to collect all relevant data, (iii) data elaboration to calculate performance at different levels of detail and (iv) result interpretation to optimise the SC. The distributed implementation of the approach at different SC steps represents a useful means to practically realise a sustainable SC management. A case study involving a leather shoe SC is used to demonstrate the effectiveness of the approach in identifying criticalities, supporting the selection of the most appropriate suppliers and correctly setting a management strategy towards the optimisation of internal and external traceability and environmental sustainability performances.     

Synthesis of macroporous ZrO2–Al2O3 mixed oxides with mesoporous walls, using polystyrene spheres as template

Macroporous ZrO₂–Al₂O₃ mixed oxides with mesoporous walls were synthesized. The three-dimensional interconnected macroporous structures, of inorganic zirconia–alumina mixed oxides containing different alumina compositions (25, 50, 100 wt%), were prepared by sol–gel method from inorganic precursors and using polystyrene microspheres with diameters of 685 and 1520 nm as templates. The final porous arrays with controllable pore size in the submicrometer range could be obtained by calcination of the organic template. The structural characteristics are discussed. The physicochemical characterization of the samples was carried out by N₂ physisorption (S_BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The shrinkage of pore diameter was approximately 35%, and the wall thickness of inorganic framework varied between 135 and 154 nm. The specific surface areas, of the samples, were between 123 and 287 m²/g, obtaining the largest surface area with the highest alumina contents and the smallest templates.     

Albumin causes a synergistic increase in the antioxidant activity of green tea catechins in oil-in-water emulsions

Model oil-in-water emulsions containing epicatechin (EC) and epigallocatechin gallate (EGCG) showed a synergistic increase in stability in emulsions containing added albumin. EGCG showed a stronger synergy (35%) with ovalbumin than did EC. Oxidation of the oil was monitored by determining peroxide values and hexanal contents. The effect of bovine serum albumin (BSA) on model oil-in-water emulsions containing each of the green tea catechins [epicatechin gallate (ECG), EGCG, EC and epigallocatechin (EGC)] was studied during storage at 30 °C. The green tea catechins showed moderate antioxidant activity in the emulsions with the order of activity being ECG ≈ EGCG > EC > EGC. Although BSA had very little antioxidant activity in the absence of phenolic antioxidants, the combination of BSA with each of the catechins showed strong antioxidant activity. BSA, in combination with EC, EGCG or EGC, showing the strongest antioxidant activity with good stability after 45 days storage. Model experiments with the catechins stored with BSA in aqueous solutions confirmed that protein–catechin adducts with antioxidant activity were formed between the catechins and protein. The antioxidant activity of the separated protein–catechin adducts increased strongly with storage time and was stronger for EGCG and ECG than for EC or EGC.     

Ultra-deep oxidative desulfurization of diesel fuel by the Mo/Al2O3-H2O2 system: The effect of system parameters on catalytic activity

This work presents the results obtained in the development of Mo/γ-Al₂O₃ catalysts and their evaluation in the oxidative desulfurization (OD) process of diesel fuel using hydrogen peroxide as the oxidizing reagent. The catalysts were prepared by equilibrium adsorption using several molybdenum precursors and aluminas with different acidity values. They were characterized by Raman spectroscopy. The effect of the reaction time, reaction temperature, nature of solvent, concentration of solvent and hydrogen peroxide, content of molybdenum and phosphate in the catalysts were investigated. The results showed that the activity for sulfur elimination depends mainly on the presence of hepta- and octamolybdates species on the catalyst support and the use of a polar aprotic solvent. Likewise, the presence of phosphate markedly increases the sulfur elimination. In this way, it is possible to reduce sulfur level in diesel fuel from about 320 to less than 10 ppmw at 333 K and atmospheric pressure. Additionally, on the basis of the results obtained a mechanistic proposal for this reaction is described, as an oxidation mechanism by nucleophilic attack of the sulfur atom on peroxo species of hepta- and octamolybdates, but a mechanism involving the singlet oxygen presence can be discarded.